1. Field of the Invention
The present invention relates, generally, to specimen collection and more particularly, to devices for collecting and/or determining the presence of occult blood in fecal matter.
2. Description of Related Art
Over 100,000 persons per year in the United States are afflicted with cancer of the colon and rectum. When the number of colon/rectal cancers occurring each year is combined with the number of cancers occurring in other digestive organs, including the esophagus and stomach, such cancers of the digestive system account for more occurrences of cancer than any other single form of the disease. Contrary to many other forms of cancer, early diagnosis and treatment of digestive tract cancer does result in a cure rate of 80% to 90%. If, however, the disease is not detected until the later stages, the cure rate drops significantly. Thus, early detection of the disease is important to successful treatment of digestive tract cancer.
Most, but not all, cancers of the digestive tract bleed to a certain extent. This blood is deposited on and in fecal matter excreted from the digestive system. The presence of blood in fecal matter is not normally detected, however, until gross bleeding, that is, blood visible to the naked eye, occurs. Gross bleeding, however, is symptomatic of advanced cancers.
Digestive tract cancers in the early stages, including pre-cancerous polyps, also tend to bleed, giving rise to occult (hidden) blood in the fecal matter. Other pathological conditions, such as Crohn's disease and diverticulitis, can also give rise to the presence of occult blood in the fecal matter.
It is known that because of the relatively high fat content of fecal matter, blood, when present, is not distributed uniformly throughout it. For this reason, obtaining multiple specimens from different areas of each bowel movement is desirable; but even a single positive test from any part of the feces should be considered a positive result.
Accordingly, test equipment and test procedures have been developed for use by physicians in testing for the presence of occult blood in fecal matter. One such test is disclosed in Pagano U.S. Pat. No. 3,996,006. In general, the Pagano test employs an absorbent paper or sheet impregnated with a guaiac reagent and encased in a special test slide having openable flaps on both sides of the test slide. To use the Pagano test slide, a specimen of fecal matter is smeared onto the guaiac impregnated paper by opening the panel or cover on one side (front) of the test slide and applying the specimen through apertures or “wells.” Thereafter, the cover is closed. The panel on the opposite side (rear) of the test slide is then opened and a nonaqueous developing solution is applied to the guaiac impregnated paper. If occult blood is present in the fecal matter smeared on the opposite side of the paper, the guaiac reaction will dye the paper blue, providing a positive indication of the presence of blood in the fecal matter.
A specific test for human hemoglobin (often referred to as an immunological or immunochemical test) has also been devised. This test theoretically registers only human hemoglobin and not animal blood from meat or other agents, and therefore, theoretically does not require the patient to be on a special diet. While the hemoglobin test has the advantage over guaiac tests of registering only human hemoglobin, the hemoglobin test is expensive for a screening test and requires specially trained individuals to perform and read the test. Such hemoglobin tests may also be administered using a slide-type devices. For example, devices may be used to collect a specimen on a removable tab, which may be removed, carrying with it the specimen for off-device testing using a hemoglobin test.
Certain potential disadvantages of the existing devices have been observed. For example, although appropriate materials are used in constructing the device, the cardboard and paper materials typically used in the construction of test devices is subject to deterioration when placed in contact with the moisture-containing specimens. Consequently, there exists a need for improved testing devices.